Dropout switch

ABSTRACT

A SWITCH FOR DIRECTING A STREAM OF FLUIDIZED PARTICULATE MATERIAL FROM A PIPELINE CONVEYOR PIPE EITHER THROUGH A BYPASS CONDUIT TO A CONTINUATION OF THE PIPE OR THROUGH AN ENLARGED CONDUIT TO A RECEPTACLE OR HOPPER. THE CONDUITS FORM A UNIT PIVOTED TO SWING TRANSVERSELY OF THE CONVEYOR PIPE AND SELECTIVELY ALIGN AND CONNECT EITHER THE BYPASS CONDUIT INLET OR THE ENLARGED CONDUIT INLET WITH THE CONVEYOR PIPE. THE ENLARGED CONDUIT FORMS AN EXPANSION CHAMBER HAVING STREAM TURNING BAFFLES DIRECTING THE STREAM THROUGH THE CHAMBER TO AN OUTLET IN THE BOTTOM.   THE OUTLET CARRIES AN O RING SEAL MEMBER WHICH IS FORCED INTO SEALING RELATION AROUND A DISCHARGE PASSAGEWAY IN A PLATE, FORMING THE UPPER PORTION OF A HOPPER, BY THE SWINGING MOVEMENT OF THE SWITCH AND SEALS THE JOINT BETWEEN THE CHAMBER OUTLET AND THE PLATE. THE PIVOT IS POSITIONED AT ONE SIDE OF THE SWITCH MEMBER CENTER OF GRAVITY SO THAT THE WEIGHT OF THE SWITCH MEMBER WILL ASSIST IN THE SEALING. THE SEAL MECHANISM FOR THE BYPASS OUTLET IS USED TO RESIST THE END THRUST ON THE SWITCH.

E. A. BARBER DROPQUT SWITCH Sept. 20, 1971 3 Sheets-Sheet 1 Filed March 4, 1970 MEL .N mEh Sept. 20, 1971 I BARBER 3,606,480

DROPOUI SWITCH Filed March 4, 1970 3 Sheets-Sheet 2 A. BARBER DROPOU'I' SWITCH Sept. 20, 1971 3 Sheets-Sheet 3 Filed March 4}. 1970 United States Patent Oihce US. Cl. 302-28 12 Claims ABSTRACT OF THE DISCLOSURE A switch for directing a stream of fluidized particulate material from a pipeline conveyor pipe either through a bypass conduit to a continuation of the pipe or through an enlarged conduit to a receptacle or hopper. The conduits form a unit pivoted to swing transversely of the conveyor pipe and selectively align and connect either the bypass conduit inlet or the enlarged conduit inlet with the conveyor pipe. The enlarged conduit forms an expansion chamber having stream turning bafiies directing the stream through the chamber to an outlet in the bottom. The outlet carries an O ring seal member which is forced into sealing relation around a discharge passageway in a plate, forming the upper portion of a hopper, by the swinging movement of the switch and seals the joint between the chamber outlet and the plate. The pivot is positioned at one side of the switch member center of gravity so that the weight of the switch member will assist in the sealing. The seal mechanism for the bypass outlet is used to resist the end thrust on the switch.

BACKGROUND In conveying sand through pipelines, the sand is suspended in an air stream and blown to a point of use. As there are often several different points of use, it is desirable to use a single pipeline and insert a switch therein which may selectively direct the streams to the desired point of use. Switches have been suggested which use a bent pipe rotatable about the longitudinal axis of one end of the pipe to align with discharge pipes arranged along the circle described by the path of the other end of the bent pipe as it is rotated. Other switches have been suggested which utilize a carriage transversely slidable on rollers and carrying a bypass pipe and a circular receptacle tangentially receiving the sand and discharging it downwardly such as shown in Pat. No. 3,174,806 to Barber et a1. issued Mar. 23, 1965.

SUMMARY OF INVENTION This invention relates to a switch for selectively directing particulate material, such as foundry sand, suspended in an air stream to either of two outlet passageways from the single supply pipeline conveyor. The switch member is an upstanding box-like structure mounted on a pivot adjacent to, but transversely offset to one side of, a lower edge, and the discharge outlet, of the switch structure. The axis of the pivot is parallel to the axis of the supply pipe. The switch member is mounted on a supporting frame and includes at least two switching conduits with spaced inlets which, by swinging the structure about the pivot, may be selectively brought into alignment with the single supply pipe fixed on the frame. One inlet connects with a pipe or conduit extending across the structure and having an outlet at the opposite side of the switch structure. This conduit forms a bypass and a continuation of the supply pipe to an outlet pipe fixed on the frame at the opposite side of the switch. The other inlet opens into the second conduit, formed by a box-like receptacle, adjacent the top thereof. A series of battles in the receptacle directs the horizontal sand-containing air stream downwardly at an angle to the inlet stream while allowing the 16%,480 Patented Sept. 20, 1971 air stream to expand, reducing both its pressure and velocity, and exit at an angle to the inlet through an outlet in the bottom of the receptacle, and through a passageway through a plane plate supported in the frame and adapted to form the top of a hopper receiving the sand. An 0 ring gasket or seal member is positioned around the periphery of a projection forming the outlet of the receptacle and directly under an outwardly extending flange forming a plane surface extending around the periphery of the projection. When the switch member is moved about its pivot to position the inlet to the receptacle, or chamber, forming the second conduit, in line with the supply pipe, the outlet of the receptacle or chamber is moved longitudinally and lowered into longitudinal alignment with the passageway through the plate. The flange plane surface is thus moved facewise and the O ring is compressed between the flange on the receptacle and the upper plane surface of the plate around said passageway and over the sharp edge of the passageway to thus seal the receptacle outlet. The inlet to the receptacle, forming the second conduit, is sealed in the well-known manner shown and claimed in the above-mentioned Pat. No. 3,174,806. The end thrust on the structure produced by turning the sand stream is resisted by the outlet pipe sealing mechanism coacting with a blind seal ring on the back end of the receptacle. The switch structure is moved between its operative positions, and the inlet and outlet pipe seals are actuated, by power means such as fluid actuated piston and cylinder motors. The weight of the structure assists in sealing the bottom of the receptacle.

An object of this invention is a switch having an outlet automatically sealed by operation of the switch.

A further object is a pivoted switch having a straight bypass pipe and movable transversely of the supply pipe.

A still further object is a pivoted switch having an expander receptacle with turning bafiies therein capable of withstanding high pressures, shock loads and wear due to abrasion of the conveyed material.

These and other objects and advantages will be apparent from the following specification and the accompanying drawings.

DESCRIPTION OF DRAWINGS FIG. 1 is a side elevation with parts broken away and the switch in the dropout position.

FIG. 2 is a partial top view of FIG. 1.

FIG. 3 is a front elevation of FIG. 1 with parts broken away and partially in section showing the switch member in the dropout position.

FIG. 4 is a front view similar to FIG. 3 with other parts broken away and partially in section showing the switch in the bypass position.

FIG. 5 is a schematic view showing two switches in series.

DESCRIPTION OF THE NOW-PREFERRED EMBODIMENT As shown in the drawings, a supply or inlet pipe 10 of a pneumatic pipeline conveying system such as described in Pat. No. 3,174,806 cited above is supported in a fixed position by a clamp 14 on a frame shown generally at 12 which is also the support for the entire switch unit. A discharge or outlet pipe 16 is similarly supported in fixed position at the opposite end of the frame. A switch member generally designated at 18 is mounted to pivot, on a shaft 20 supported in bearings 22, between and transversely of the supply and discharge pipes 10 and 16. The frame 12 which consists of upright and transverse structural members is mounted on and secured to a fiat plate 24 extending the entire length and width of the frame. The bearing members 22 are mounted in fixed position on the plate 24 and thus serve to pivot the entire switching element in the frame 12. The axis of the pivot, and shaft 20, is substantially parallel to the axis of the inlet or supply pipe 10.

The switch element shown generally at 18 comprises a front plate 26, a back plate 28 and a straight through or bypass conduit 30 extending between, through and connecting the two end plates. A second conduit in the form of a discharge box or expansion chamber 32 arranged at one side of conduit 30 is formed between the plates 26 and 28 by securing the open sides of a U-shaped member 34 to the plates 26 and 28 thus closing the ends of the U-shaped member to form a discharge box 32 between the end plates with a downwardly directed discharge opening or outlet 36 adjacent the lower edge of the plates. A series of baflies 38 extend between and are secured, as by welding, to the sides of the U-shaped members. These baffles or shelves form a series of pockets having a progressively smaller depth from the top to the bottom of the discharge box and together with the sand entrained in the pockets serve as a turning vane to turn the generally horizontal stream of fluidized particulate material to any desired angle which in the now-preferred embodiment is in a generally downwardly directed stream. The sides of the switch element including the through pipe 30 and the discharge box 32 are secured to the pivot shaft 20 by means of a front channel member 40 secured to the front plate 26 and a rear channel member 42 secured to the rear plate 28. The axis of the pivot shaft 20 is substantially normal to the front and rear plates 26, 28.

The discharge box 32 due to its enlarged cross sec-' tional area compared with the cross sectional area of the supply pipe and due to its enlarged discharge orifice 36 compared with its inlet orifice acts as a diffuser or expansion chamber in which the velocity and the pressure of the entering air and sand stream is materially reduced so that the stream is discharged longitudinally of the discharge outlet 48 in the plate 24 at an angle to the inlet stream and at a much reduced pressure and velocity.

Channel members 44 secured to the sides of the U- shaped member 34 extend between the channels 40 and 42 and together with the channels 40 and 42 form an outstanding flange 46 forming a plane surface extending all the way around the lower portion of the discharge box formed by the two plates 26-28 and the U-shaped member 34.

The plane plate 24 has a discharge aperture 48 therethrough which, when the switch is in the dropout position shown in FIG. 3, is aligned, and mates, with the outlet 36 of discharge box 32. A strip of packing material forming a seal member 50 is positioned around the lower outside periphery of the discharge box 32 adjacent the flange 46 and is held in position by a retainer 52 secured to the outside of the discharge box outlet. The aperture or passageway 48 in the plate 24 is large enough to receive the lower end of the discharge box and the retaining ring 52 with a small working clearance. The packing ring 50 may be an O ring of resilient material such as neoprene or it may be a length of tubing material having say a 4 inch bearing on the upper plane surface of the plate 24 and by the application of downward pressure to the flange 46 be deformed so as to extend around the relatively sharp edge of the aperture at the upper surface of the plate 24 and hence form a tight seal between the discharge box outlet and the plate 24. This seal can thus accommodate any slight amount of sand that might accumulate on the upper surface of plate 24 adjacent the edge of the aperturc.

As shown in FIG. 3 the shaft 20 is secured to the switch element 18 adjacent the lower edge of the switch element and spaced or offset to one side of the center of gravity of the element so that the weight of the switch element assists in holding the element down onto the packing '0 and the plate 24 in the dropout position shown in FIG. 3. The axis of the pivot, and shaft 20, is offset to one side of the outlet 36 of the discharge box or expansion chamber 32 and is approximately in the plane of the outlet 36 and the upper surface of plate 24.

A structural member 54 extends to one side of the frame member 12, and carries a support 56 for pivotally supporting power means such as a piston and cylinder construction 58 which is pivotally connected at its other end by angle iron 60 and pivot pin 62 to one side of the U-shaped member 34. Application of fluid pressure to one end or the other of the piston and cylinder member 58 will move the switch element 18 to and from the dropout position, shown in FIG. 3, and from and to the bypass position sown in FIG. 4. Application of pressure to one side of the member 58 will assist the weight of the member 18 in compressing the packing 50 and sealing the outlet of the discharge box 32. The final dropout position of the switch element 18 is accurately determined by adjustable stop members 64. Application of pressure to the other side of element 58 after swinging the switch element 18 upwardly about the axis of shaft 20 will accurately determine the upper position of the switch element by holding one side of the discharge box 32 against the adjustable stop member 66. Structural element 54 is centrally located between the front and the back frame members. The bottom plate 24 supporting the frame member 12 and the switch 18 is adapted to be secured in fluid tight relation to the top of a hopper or other receptacle for receiving the sand discharged from the expansion chamber 32 forming the second conduit. The hopper or receptacle 86 is provided with the usual filtering or separating mechanism not shown to permit the release of the air forced in with the air stream but prevent the escape of the sand.

Sealing means similar to that shown in Pat. No. 3,174,806 cited above may be used for sealing the inlet and outlet of the bypass pipe 30 and the inlet to the discharge box 32. Reference may be made to said patent for a more detailed description of the sealing mechanism which is only generally described herein. The front plate 26 of the switch element 18 has an aperture or passageway 68 therethrough forming an inlet to the chamber 32. Secured to the front face of the plate 26 and surrounding the aperture is an annulus 70 having an annular recess therein for receiving packing material 72. The inner diameter of the recess is substantially the same as the outer diameter of the supply pipe 10 so as to telescope with the sliding member 74 used to compress the packing 72 in sealing the inlet to the discharge box or chamber 32. The sliding element 74 is moved back and forth by power means such as fluid actuated piston and cylinder construction 76 acting through a yoke 78 pivoted at 80 on the frame member 12. Actuation of the piston and cylinder members 76 will move the sliding member 74, which acts as a seal on inlet pipe 10, back and forth on inlet pipe 10 to either compress the packing 72 and seal the inlet to the chamber 32 or move the sliding member 74 back out of the way so that the switch element 18 may be swung past the inlet pipe 1 0 and the sliding member 74 so as to bring the sealing element on the through conduit 30 into line with the sliding element 74. A similar structure is provided on the back plate 28 with the exception that the sealing member 82 is not an annulus but is a solid disc which will block the aperture 76 in thte plate 28 and is therefore a blind seal. This blind seal contains a similar annular recess housing the packing material and otherwise acts in a manner similar to that described for the annulus 70. When in the position shown in FIG. 1 the sliding member 84, which is similar to the sliding member 74, acts, when actuated by power means 76, to apply pressure through the blind seal 82 to the back plate 28 of the discharge box 32 and thus supply a force opposing the lateral force on the discharge box 32 and the switch member 18 produced by the impact and the turning of the pressurized stream of fluidized sand introduced into the discharge box through the inlet orifice 68 in the front plate 26.

OPERATION Assuming the switch to be in the position shown in FIGS. 1, 2 and 3 and referring to FIG. 5, sand from the mixing chamber 88, where the sand and air is suitably mixed to fiuidize the sand, is forced through inlet pipe past the sealing mechanism 70, 72, 74 through the inlet orifice 68 and into the expansion chamber 32 at relatively high pressure, say 100* pounds and at a high velocity. The sand collects at the back of the discharge box or expansion chamber 32 in the pockets formed by shelves 38 and together with the shelves forms a turning vane which will direct the sand downwardly and longitudinally out through the outlet orifice 48 in the plate 32' at the same time reducing both its pressure and velocity. The sealing mechanism at the back of the discharge box serves to oppose the reaction force of turning the direction of the sand and air stream. The sand is fed through the expansion chamber and into a receptacle or hopper 86 located beneath the switch mechanism. After the desired quantity of sand has been blown into the receptacle 86, the supply of sand to the mixing chamber is stopped and air alone is blown through the supply pipe 10 to purge the entire pipeline of sand.

If it is now desired to fill a second receptacle 90 spaced from the first receptacle 86, the piston rod side of the fluid motor 58 is energized, preferably by the supply of compressed air, although it should be understood that the motor 58 might be hydraulically actuated or even be an electric motor, to withdraw the piston rod and move the switch element 18 from the dropout position shown in FIG. 3 to the bypass position shown in FIG. 4 thereby lifting the expansion chamber up off of the plate 24 and bringing the bypass pipe 30 into line with the sliding members 74 and 84 of the sealing mechanisms. Assuming that the switch element for the receptacle 90, which is the same as that for receptacle 86', which has been described herein, is in the dropout position shown in FIG. 3, then the stream of sand and air supplied through the supply pipe 10 will now pass through the through conduit 30 of the switch element for receptacle 86, completely bypassing the receptacle 86, and enter the expansion chamber 32 of the switch mechanism on receptacle 90. The action will then be the same for receptacle 90 as that just described for receptacle 86. Expansion chamber 32 when lifted as shown in FIG. 4 will have its discharge outlet 36 directly above the discharge outlet 48 in plate 24 sothat any stray sand coming out of the discharge outlet while it is being raised or while it is in its raised position will fall through the outlet and largely avoid any accumulation of sand on the upper surface of the plate 24, adjacent the aperture 48 which might render the sealing of this joint more diflicult.

If it is desired to again supply receptacle 86 with sand the motor 58 is again energized to move it in the opposite direction and return the annulus 70 into alignment with the inlet pipe 10 and the sliding member 74 and the through conduit 30 against the adjustable stop 64 which will accurately align the members 70 and 74 of the sealing means. The Weight of the switch member 18 being olfset from its pivot 20 will assist the motor 58 in moving the switch to its dropout position and also assist the motor in compressing the seal 50* to secure a tight joint between the discharge box and the plate 24. The center of the expansion chamber, or second conduit, outlet moves longitudinally through an arc about the pivot 20 and the axis of the outlet 36 of the chamber and the axis of the discharge passageway 4-8 are arranged tangent to that arc so that the outlet and the discharge will mate and seal when the switch is in the dropout position of FIG. 3. It is to be understood that the lines are completely purged after each blow so that the lines are as completely free of sand as possible before the switch mechanism is actuated. A set of limit switches for each position of the switch mechanism and each position of the sealing mechanism may be utilized and connected through a control box to automatically provide the proper sequence of actuation of the several motors.

While the preferred embodiment of this invention has been illustrated and described, it is to be understood that such is merely illustrative and not restrictive and that variations and modifications may be made therein without departing from the spirit and scope of the invention. Accordingly it is not desired to be limited to the precise details set forth but to take advantage of such changes as fall within the purview of the invention.

What is claimed is:

1. A switch for pipeline conveyors comprising a frame, an inlet pipe fixed in said frame and an outlet pipe fixed in said frame and spaced from said inlet pipe, a switch member pivoted in said frame, a plurality of switching conduits carried by said pivoted switch member for movement with respect to said frame, transverse of, and into selective alignment with, said inlet pipe, one switching conduit comprising a through conduit having an inlet and an outlet aligned simultaneously with said respective inlet and outlet pipes, a second switching conduit comprising an expansion chamber including stream turning means and having an outlet directed at an angle to said inlet pipe, a pivot for said switch member having an axis spaced from and parallel to said inlet pipe, and offset to one side of said second conduit outlet.

2. A switch as claimed in claim 1 in which said frame includes a discharge outlet having a substantially plane surface facing said switch member, and mating with said second conduit outlet in one position of said switch member.

3. A switch as claimed in claim 2 in which said second conduit outlet includes a plane surface, movable facewise into mating relation with said discharge outlet plane surface.

4. A switch as claimed in claim 2' including a seal member between said discharge outlet and said second conduit outlet.

5. A switch as claimed in claim 4 in which said one conduit is arranged along one side of said second conduit and said pivot is located on the opposite side of said second conduit and the center of gravity of said switch member is on one side of said pivot with said switch member in said one position and assist in forcing said discharge outlet and said second conduit into mating and sealing relation.

6. A switch as claimed in claim 2 in which said frame includes a plane plate in which said discharge outlet is formed and on which said pivot is mounted.

7. A switch as claimed in claim 2 in which said second switching conduit has an outstanding flange surrounding its outlet and sealing means comprising a packing surrounding said conduit adjacent said ilange and power means for moving said switch member to align said inlet pipe and said second conduit inlet and compress said packing between said flange and said plane surface.

8. A switch as claimed in claim 1 in which the outlet for said second conduit is moved longitudinally through an arc in moving the inlet to said second conduit into and out of alignment with said inlet pipe, a discharge outlet having alongitudinal axis, said second conduit outlet being moved longitudinally into axial alignment and mating and sealing relation with said discharge outlet by movement of switch member to align said inlet pipe and said second conduit inlet.

9: A switch as claimed in claim 1 in which said one conduit is arranged along one side of said second conduit and said pivot is located on the opposite side of said second conduit.

10. A switch as claimed in claim 1 in which said one conduit is a straight pipe and said outlet pipe is aligned with said inlet pipe, sealing means for the joint between said one conduit and said outlet pipe including power means applying an axial force to said switch member opposing the reaction of the turning stream in said second 7 conduit when said second conduit is in alignment with said inlet pipe.

11. A pivoted switch member comprising a pair of spaced end plates, a bypass conduit supported by said plates and having an inlet end supported in one plate, a U-shaped member between said plates and Welded at its open sides to a respective end plate to close the open sides and with said plates form an expansion chamber, an inlet to said chamber in said one plate, an outlet for said chamber defined by the open end of said U-shaped member and said sides, a pivot for said switch member having an axis spaced laterally from said outlet opening and substantially normal to said plates.

12. A switch for a pipeline conveyor comprising a frame, an inlet pipe secured to said frame, a plate, having a discharge passageway therein, secured to and under said frame, a movable switch member pivoted on said plate and including an expansion chamber having an inlet and a downwardly directed outlet, a seal secured to said outlet, said expansion chamber movable, by movement of said switch member about said pivot, from a position in which said downwardly directed outlet is directly over said discharge opening and said inlet misaligned with said pipe to a position in which said inlet is aligned with said pipe and said outlet mates with, and is forced by said movement into sealing relation with, said discharge opening.

References Cited UNITED STATES PATENTS 2,690,931 10/1954 Baresch 30228 2,825,604 3/1958 Sebestyen 302-28 2,895,768 7/1959 Bray, Jr. 30228 3,174,806 3/1965 Barber et al. 302-28 ANDRES H. NIELSEN, Primary Examiner 

